1. Field of the Invention
The invention relates generally to the usability of the computer-human interface and, more specifically, to defining a toolbar that enables the user to activate any displayed icon via a short, radial mouse traverse
2. Description of the Prior Art
The Compact American Dictionary of Computer Words (Houghton Miffin Co., 1998) defines a toolbar to be an artifact “. . . in programs using a graphical user interface [having] a row of icons across the top of a window that serve as buttons to activate commands or functions.” This disquisition designates icons displayed in this manner to be the Traditional Toolbar style (hereafter TTB). Vendors employing the TTB design commonly pair icons displayed with a leaf of the menu system such that a click on an icon results in a transformation to the same computer state that results from a traverse of the menu system that activates the menu leaf with which said icon is paired. Various other controls such as list boxes and spin buttons may be embedded in a TTB and function in the same manner as when presented via any other display method. Each of the major operating system vendors publish design guidelines for horizontal style toolbar promoting features such as these. See: The Windows Interface Guidelines for Software Design, Microsoft Press, 1995; MacOS 8: Human Interface Guidelines, Apple Computer Inc, 1997; Visual Design With OSF/Motif, HP Publishing, 1990; Java Look and Feel Design Guidelines, 1999, Sun Microsystems Inc., NeXTStep Concepts, NeXT Computer Inc., 1990; Open Look: Graphical User Interface Functional Specifications, Sun Microsystems Inc., 1990. Numerous generic publications also recommend this format, a recent reference being Susan Fowler, GUI Design Handbook, 1998.
These cited materials well reflect the level of the prior art. Objective research available through government and the academic sources evaluating characteristics of the TTB format is not extensive. Even less research exists that relates to alternate toolbar formats. As example, Mayhew (Deborah J. Mayhew, Principles and Guidelines in Software User Interface Design, 1992), exhaustively summarizes relevant research in the field of computer-human interface design; devoting Chapter 9 to the concept of direct manipulation interfaces. Of the 41 pages of Chapter 9, 17 pages are devoted to summarizing research on icon design and usage. Mayhew does not cite either research that shows the TTB to be the best of all possible designs or research investigating how icon displays can be alternately formatted to produce a more usable toolbar.
Some non-TTB formats do exist. For several years, the Logitech Corporation has bundled with its advanced mouse products a non-traditional toolbar that displays a non-varying set of eight icons arrayed around a central square that is popped-up at the click of a specially assigned mouse button. While the functionality provided by this Logitech offering is well selected, the design has certain shortcomings: (1) the number of icons displayed is limited, (2) users cannot specify the icons displayed, and (3) the central-area is used only to terminate the display. In 2001 Logitech introduced another non-standard toolbar based on a pop-up, ten-segment pie menu that offers rapid access to the options designed into the toolbar by Logitech personnel. While this capability provides an imaginative user-friendly means to expeditiously perform several navigational tasks of an Internet browser, as with the earlier Logitech offering the number of icons provided is limited. Due to limitations inherent to the pie menu design the number of options offered must remain limited to about eight selections.
Horton (William Horton, The Icon Book: Visual symbols for computer systems and documentation, 1994, pp. 364-373) presents a non-traditional toolbar display when considering how to design an icon display. Horton considers rectangular displays, some of which contain embedded blank areas. As with the Logitech embedded blank, Horton's blank does not aid the management of the icon display. Additionally Horton offers no advice of where the display is to appear on the active display nor does he apprise the issue of minimizing the total amount of traverse required to manipulate his icon display.
A significant problem with the TTB is how to manage toolbar widths when they do not extend approximately the width of the active display. When the width of a TTB modestly exceeds the screen width, the vendor may provide a scroll capability within the toolbar body, which while permitting display of all icons, can require substantial cursor movement and be time consuming. Another design characteristic of this toolbar style is encountered when the aggregate width of all icons to be displayed greatly exceeds screen width. The common solution is to offer multiple rows of icons displayed under the menu bar even though this may result in a toolbar display that permanently occupies as much as 10-15 percent of total screen real estate.
Vendors employing the TTB design commonly provide a means by which the user can customize the display. With customizable toolbars it is generally possible for the user to arrange a toolbar's icons into spatially distinct groups having cognitive meaning to the user while additionally permitting the user to arrange icons within each group in whatever order desired. The user who applies customization wisely is better able to recall each icon's location while reducing the total traverse distance required during toolbar manipulation.
FIG. 2 presents several variations of the toolbar display suggested by the present invention to provide more expeditious access to desired icons. The basis of this format is a set of contiguous, irregularly shaped “Toolbar Regions” (generally referenced more succinctly hereafter as “Regions”) radiating outward from a point that defines the origin. A left half of the graphic is designed to enable each region to converge on the origin point from the left. A similarly aligned set of regions is positioned to the right of the origin point with convergence on the origin point from the right. Zero or more icons may be displayed within each toolbar region. Optionally attached to each icon is a label identifying the icon's purpose. Each icon and any accompanying label is bounded in a manner to define a “Target Icon”; i.e., the sub-area of the hosting region surrounding the icon and a possible label that can activate the icon. For succinctness target icons will generally be referred to as “Targets.” In FIG. 2 all examples having identification that end with “1” display unlabeled icons within a target that is generally but need not be rectangular. Similarly, examples of FIG. 2 with identification ending in “2” display labeled icons in a generally non-rectangular target that makes possible a label that is generally longer than if label length was limited to icon width. It will become apparent during discussion of Fitts' Law below that this trapezoidal target configuration generally permits target acquisition using shorter cursor traverses than otherwise required thus making possible more rapid activation of a desired icon than is possible via a TTB format that offers the same icon set. The diagrams of FIG. 2 obviously do not present a full display of representative icons, as it is apparent from the design that presence of additional icons is implied.
Superimposed over and centered on the origin is a “central-area” comprising a set of irregular “Sub-Areas” herein called “Shapes.” For any particular display the shapes that form the central-area are normally configured to permit selection with the least physical effort. While not required, it is recommended that the central-area configuration include at least a shape that terminates the toolbar and a shape that replaces the toolbar display with the application's main menu display. If the current display is a descendant of the toolbar generated at toolbar activation, one or more central-area shapes are normally provided to enable the user to redisplay any desired ancestor toolbar. This is illustrated by FIGS. 2D1 and 2D2. Additional shapes in the central-area may provide activation of a limited number of functions. When the central-area is so employed, the invention recognizes that exigencies of a particular implementation may assign any function to the central-area; such functions generally comprising the most frequently utilized application functions, major system functions, or toolbar management functions.
The inventor names the graphic resulting from superimposing the central-area over the aggregation of toolbar regions the Spider ToolBar (hereafter STB) due to a perceived resemblance to a spider web when non-rectangular targets are displayed in the manner suggested by FIG. 2H2
To utilize this invention the user activates the toolbar system via a middle button click, simultaneous multi-button button click, simultaneous stroke of one or more keyboard keys, or other appropriate unique action. The STB is popped-up with the cursor jumped under program control to a location near the center of the central-area. For one designated “primary” and one designated “secondary” target of each region the STB provides for target acquisition via a technique termed “remote acquisition”. When the mouse is employed for target acquisition, remote acquisition entails traverse into any non-target area of the region displaying the desired target and single clicking to acquire the primary or double clicking to acquire the secondary target. Each primary target is differentiated from the “standard” targets of its region by unique color as proposed by the preferred implementation, by geometric shape as illustrated by FIG. 1B, by physical location, or by any other suitable distinguishing characteristic. The secondary target is similarly identified but employs a characteristic that differentiates it from the primary target. The user is always able to acquire any target via “direct” acquisition; namely, a traverse of the cursor into the bounds of the desired target and performing the appropriate selection action. At completion of either a remote or direct target acquisition, the action attached to the target is performed. Once a selection is made the STB is unpainted unless the toolbar permits multiple selections or the functionality activated initiates display of a child or ancestor of the current toolbar. Depending on prior user parameterization, at STB termination the cursor either remains at its current location or is returned to the location occupied prior to STB activation.
This disquisition has offered a description of the TTB and another of the STB but has provided little indication of why the STB represents an innovative and beneficial improvement over the prior art. These benefits will become apparent by an appraisal of the comparative impact the TTB and STB designs have on parameter values of Fitts' Law (Paul M. Fitts, “The Information Capacity of the Human Motor System in Controlling Amplitude”, Journal of Applied Psychology, 1954, pp. 381-391) which is the criterion employed by most human factor professionals to estimate the time required to perform a target acquiring activity on a computer-human interface. Low values of “T” are generally considered to reflect high productivity. A conventional rendering of Fitts' Law is:   T  =      a    +          b      ×                        log          2                ⁡                  (                                    D              W                        +            1                    )                    where:                T→Total time to locate and acquire a desired target (seconds)        a→Time required to identify the desired target (seconds)        b→Rate at which the musco-skeletal system transmits information (seconds/bit)        D→Distance to desired target (inches)        W→Width of desired target (inches)        
To ascertain characteristics of toolbar design conducive to low values of “T” we will first review the professional literature to identify factors that influence values of “a” then ascertain whether the TTB or STB format is most conducive to low “a” values. An equivalent approach is then applied to appraise the logarithmic component of Fitts' Law.
The speed at which a desired icon can be located is correlated to the level of experience of the user. The novice user generally expends visual search time to locate the icon while the expert user will generally know the location of frequently used icons. Analysis of the time required for the novice to locate a desired icon entails the dual process of determining whether icons currently within the user's foveal vision contain the desired icon and when the desired icon is not in foveal vision how many saccades will be required to bring it into foveal vision. Williams (Leon Williams, “Studies of Extrafoveal Discrimination and Detection”, Visual Search, 1973, pp. 77-92) investigated the ability of human extrafoveal vision to discriminate objects evidencing different color, size, and global shape properties from a background of objects with different values for these properties. Color was found to be most discriminable in extrafoveal vision followed by size, then shape. Overall issues of how screen real estate is allocated generally dictate that icon dimensions are specified based on criteria other than making icons most discriminable. Systematic use of either color or size to aid icon identification has not been extensively exploited. Research into the ability of extrafoveal vision to discriminate icons has thus emphasized investigation of icon shape. Widdel (Heino Widdel, “A Method of Measuring the Visual Lobe Area”, in R. Groner, C. Menz, D. F. Fisher, and R. A. Monty (eds) Eye Movements and Psychological Functions: International Views, 1983, pp. 73-83) defines the visual lobe area to be “. . . the peripheral area around the central fixation point from which specific information can be extracted and processed” (p. 73). Widdel employed shape and color to determine dimensions of the visual lobe area. In a first experiment Widdel randomly positioned a square having a unique internal feature in a background of varying density that comprised the same sized squares but with a different internal feature. Widdel concludes that the visual lobe area subtends 5.5° with a low-density background and 2.7° with a high-density background. A second experiment concluded that green is the color most readily discriminated followed closely by violet. Blue and red evidence approximately equal discriminative powers but less than violet. Yellow was found the color providing least discrimination. Research by Kapoula (Zoi Kapoula, “The influence of Peripheral Preprocessing on Oculomotor Programming in a Scanning Test”, in Groner op. cit., pp. 101-114) employed a text format comprising single characters of varying global and interior features. Kapoula determined that the presence or absence of peripheral information notably impacted the duration of foveal processing time and the manner of scanning for the target character. Arned (Udo Arned, Kluas-Peter Muthig, and Jens Wandmacher, “Evidence for Global Feature Superiority in Menu Selection by Icons”, Behavior and Information Technology, 1987, pp. 411-426) compared search times using iconic menus where the search characteristics were based either on global features or on local, representational features. Defining articulatory distance as the gap between the concept being communicated and the form of its physical representation, the premise tested was whether a menu that is based on an icon with global features discriminable in extrafoveal vision but with a difficult to learn large articulatory distance was manipulated less or more rapidly than a menu displaying icons with representational features discriminable only in foveal vision but with a small, easy to learn articulatory gap. For icon based menus having one dimensional format; i.e., similar to the traditional toolbar, the Arned study concluded that: “. . . although the abstract icons were designed to be maximally dissimilar to each other . . . and to provide only weak retrieval clues with respect to options they portray, they were found to be far superior with respect to both speed and accuracy. . . ” and that “. . . since search times for abstract icons were found to be fairly independent of menu size it can be concluded that icons containing global features . . . can be searched in parallel.” (p. 424). Arned concluded that disproportionate advantages accrue to menus designed with strongly discriminable global features because of parallel processing in extrafoveal vision made possible by such features. Recent research by Hornof (Anthony Hornof and David Kieras, Cognitive Modeling Reveals Menu Search is Both Systematic and Random”, CHI 97 Proceedings, 1997, pp. 107-114) concludes that: “. . . people do not . . . decide on menu items individually, but rather process many items in parallel.” (p.114) This shows that the prior art accepts the reality of parallel processing of discriminable items. However, the Arned study does conclude that representational icons are more understandable and thus learned more rapidly than icons discriminated by abstract, global features.
Inferences drawn from these researches lead to the conclusion that the STB format is more conducive to low values of Fitts' “a” than is the TTB format. One factor influencing “a” is the number of saccades required to locate an icon. Since it is known that the average saccade requires 30-120 ms while a fixation typically lasts 200-600 ms, if mean values for the saccade and fixation are presumed each fixation saved by the STB format reduces Fitts' “a” by perhaps 0.5 second. We can look to the cited research to ascertain whether the STB or TTB format is more likely to require a lower average number of fixations to foveate the desired icon. Kapoula shows that extrafoveal vision directs the goal of the next fixation while Arend showns that parallel processing increases the likelihood that the next fixation will place the target icon within foveal view. While specific research cannot be cited that directly investigates human ability to discriminate icons in extrafoveal vision displayed in two-dimensional arrays, certain inferences can be drawn. Widdel's visual lobe area of 5.5° spans somewhat more than 150 pixels at a normal viewing distance of 18 inches. A 17-inch screen provides a maximum horizontal width of approximately 12 inches. Using the Microsoft Word TTB as representative of unlabeled, rectangular icons displayed by on a screen of 1024×768 pixel density, a typical square TTB icon might have a width of approximately 18 pixels. This means that as many as eight horizontally contiguous icons can fall within extrafoveal vision per fixation. It is possible to display over 40 icons of the suggested size per twelve-inch row of a TTB display. This number suggests that even if non-overlapping fixations are assumed and irrespective of the number of icon rows displayed, a full search of the toolbar can require as many as five or six fixations. Given the same physical display device and the same icon set, a STB will display the icon set in two two-dimensional, vertical columns. Unpublished research by the inventor suggests the maximum number of regions per side of the display should not exceed seven or eight regions. Since Arned shows that the visual lobe area is approximately circular, a user should be able to place all icons of the left column within the extrafoveal vision by fixating on the middle of the left column and place within foveal vision a desired icon present in the left column with a second saccade. The search for a desired icon on the display's right can be similarly evaluated. It is therefore concluded that—on average—the STB format is expected to require fewer fixations than the TTB format to place the desired target in foveal vision. As noted above, for each fixation saved by the STB relative to the TTB, the value of “a” decreases by perhaps 0.5 second. While data are unavailable to quantify this conclusion the direction of this effect is expected to be as predicted here. If however the icons displayed rely primarily on representational features to discriminate each icon's purpose, Arned's research implies that there will be a diminution in the difference between the average number of fixations executed by the STB and TTB formats needed to bring a desired icon into foveal vision. In this case, the strength of the proceeding will be diminished although its direction will remain unchanged.
It is important to consider additional research to determine how a toolbar can be made more learnable and to ascertain whether the TTB or the STB format is easiest to learn. Muter (Paul Muter and Candance Mayson, “The Role of Graphics in Item Selection from Menus”, Behavior and Information Technology, 1986, pp. 89-95) conducted some of the early investigations encompassing iconic based menus. In this research Muter compared menus that contained labels only, icons only, and labeled icons. His findings indicated that targets containing both icons and labels produce fewest errors. Brems (Douglas Brems and William Whitten, “Learning and Preference for Icon-Based Interface:, Proceedings of the Human Factors Society—31 Annual Meeting, 1987, pp.125-129) shows that the icon only menu is the style least preferred by novices while the label only and the labeled icon styles were deemed equally desirable by more experienced users. Wiedenbeck (Susan Wiedenbeck, “The Use of Icons and Labels in an End User Application Program: An empirical study of learning and retention”, Behavior and Information Technology, 1999, pp. 68-82) enhanced these results by investigating the three menu formats in an environment of typical complexity. Wiedenbeck concludes that although the value of labels accompanying icons is short-lived, the labels are highly relevant to speed of learning while additionally providing greater perceived ease of use. She recommends toolbar designs that initially offer labeled icons but provide a mechanism that permits easy label removal. Since Wiedenbeck comments about the savings of screen real-estate by removal of icon labels, it follows that she envisages permanent display of icon labels during the learning period rather than providing labels using the popular “hint” techniques. It can be presumed that the presence of permanent labels obviates the need for the novice to learn management of “hint” labels.
A STB capability not currently available to TTB designs is the ability to fulfill Wiedenbeck's recommendation. If labels limited to the width of an icon were attempted labels would be limited to about four characters, which is insufficient unless abbreviations are employed. An extensive literature, not here cited, generally concludes that use of abbreviations should be minimized. Replacing the generally square targets of current TTB formats with rectangular targets would reduce the targets per row of horizontal display. This would decrease the number of icons subtended by extrafoveal vision per fixation with a consequent increase in the average number of fixations required to identify the desired icon. If non-rectangular targets of the type shown by labeled icons of FIG. 2 were employed in a TTB, the STB would still place more targets in extrafoveal vision than an equivalent TTB, thus still favoring the STB format. Some traditional toolbars offer “hints” that temporarily display an identifying label to an icon. This approach generally provides a pop-up textual identifier whenever the cursor is paused for approximately one second over a toolbar target. Although once activated, “hints” of successive contiguous targets are instantly displayed upon cursor entry into their bounding rectangle, the hint capability must generally be reinitiated whenever the user's horizontal traverse along the tool bar area inadvertently exits the tool bar area. Employment of the pop-up hint capability has the disadvantage of forcing the user to process target-icons in serial manner rather than in the more efficient parallel manner which human capabilities do permit.
Berlyne (D. E. Berlyne, Aesthetics and Psychobiology, 1971) identifies several characteristics of document layout that influence how users orientate and navigate a new document—as opposed to extraction of specific information from a document. Of the characteristics identified by Berlyne that of complexity is most likely to be experienced differently with the TTB and STB formats. Two aspects of complexity are to be considered: (1) the number of individual groupings and (2) the relative positioning of the groups. Tullis (Thomas Tullis, “The Formatting of Alphanumeric Displays: A Review and Analysis”, Human Factors, 1983, pp.657-682) quantifies both of these aspects by first defining a group to be: “. . . any interconnected set of characters . . . separated by less than a threshold value. . . ” (p. 671). Tullis concludes a group should not subtend a visual angle exceeding 5° which is effectively the size of the visual lobe area determined by Widdel. Tullis argues that “. . . based on knowledge of the location of some [groups] . . . one should be able to predict the locations of others” (p. 674). Tullis quantifies the complexity of inter-group locations by defining arbitrarily positioned horizontal and vertical datum lines. Tullis then counts the number of different distances from the vertical datum to a vertical edge of the bounding rectangle of each group. The same is done from the horizontal datum to a horizontal edge of the bounding rectangle of each group. Applying Shannon's Information Theory, Tullis determines the number of bits of information required to identify the position of each group relative to the position of other groups. He defines this result to be the measure of inter-group complexity.
Excluding implications of the STB central-area as this adds capability to a STB toolbar not generally available to a TTB, it can be assumed all TTB have a means of delimiting icon groups in a manner that satisfies Tullis' definition of a group: Some vendors achieve this with a vertical group delimiter, others might employ a space, etc. Similarly, the horizontal rows of icons will provide the relative vertical distances for the TTB format. The bounding rectangles of the individual icon groups will meet Tullis' definition of a group. With the STB format, the horizontal relative distances are to the sides of the vertically aligned columns while the vertical relative distances are the distances to the top or bottom of each bounding rectangle. With the STB format there are thus two horizontal distances and a number of vertical distances equal to one-half the number regions. With a TTB format, the number of different vertical distances will equal the number of icon rows displayed; commonly two or three. Because toolbars provided with commercially available application software generally contain other than equal numbers of square icons of fixed size, the sides of the icon groups generally will not be aligned when multiple rows are present. This means that there will be one horizontal distance per icon group. The STB will thus typically have: (1) a number of horizontal distances equal to or less than the number of vertical distances of a TTB and (2) a number of vertical distances equal to approximately one-half the number of horizontal distances of a TTB. Therefore it can be concluded that the inter-group complexity of the typical STB format is less than that of an equivalent TTB. It is thus expected that the influence of inter-group complexity on Fitts' “a” will more favorable to the STB format than to an equivalent TTB.
Teitlebaum (Richard Teitlebaum and Richard Granda, The Effects of Positional Consistancy on Searching Menus For Information”, CHI '83 Proceedings, 1983 pp. 150-153) investigated another design feature conducive to low values for “a.” Teitelbaum showed that experienced users utilizing a menu of consistent target positions perform a set of representative tasks in 58% of the time required when the target locations are not fixed. Somberg (Somberg, “A comparison of Rule-based Positionally Constant Arrangements of Computer Menu Items”, CHI+GI 1987 Conference Proceedings: Human Factors in Computing Systems and Graphics Interface, 1987, pp. 255-260) corroborates this result. This result is further corroborated by Mitchell (Jeffrey Mitchell and Ben Schneiderman, “Dynamic Versus Static Menus: An Exploratory Comparison”, SIGCHI Bulletin, 1989, pp. 33-37) who found that users facing a static menu performed required tasks in 56% of the time required by users facing a dynamic menu; a result very similar to that of Teitlebaum. In general it can be expected that benefits of positional consistency will be experienced equally by both TTB and STB users unless there exist characteristics of one format that permit it to be the more productively utilized than the other format. To the extent that this effect exists, a user's interest in identifying the most advantageous primary and secondary icon of each region will make the STB user more cognizant of benefits derived from optimizing the set and positioning of target-icons. It can thus be anticipated that STB users will not only appreciate the benefits of a static display but, as detailed below, will also likely better locate the icons to minimize the physical effort of their acquisition. It can even be expected that such users will better identify those icons predefined by the vendor that are infrequently used and remove them to further reduce the effort expended during toolbar manipulation.
The   bx  ⁢           ⁢            log      2        ⁡          (                        D          W                +        1            )      component of Fitts' Law measures the time needed to perform the cursor traverse that acquires a target. The constant, “b” is the inverse of bandwidth, i.e., the speed at which the human musco-skeletal system transmits bits of information. The muscle groups principally involved in mouse management determine the value of “b” with arm movements primarily engaged to perform long traverses whereas those muscle groups controlling wrist and finger motion are engaged to perform short traverses. In the article cited, Fitts notes that arm movements have higher values for “b” than do wrist and finger movements. The present invention enables right-handed mouse users to acquire targets in the upper-left and lower right quadrants via short, radial traverses controlled primarily by finger motion and traverse into the other quadrants controlled by a combination of wrist and finger motion. The reverse of this applies to left-handed users. It follows that the toolbar design that replaces the long, two-way, arm-controlled traverses to the screen's upper edge required by the TTB design with the short wrist and finger controlled traverses of the STB is the more advantageous design.
It is shown by MacKenzie (I. S. MacKinzie and W. Buxton, “Extending Fitts' Law to Two-dimensional Tasks”, Proceedings of CHI '92, 1992, pp. 219-226) that the logarithmic portion of Fitts' Law, termed the Index of Difficulty by Fitts' (hereafter ID), fails to provide objective definitions for the “D” and “W” parameters when applied to many computer interface targets. The present inventor addressed this failing by assuming users envisage an “implicit” circular target within the actual target centered on the bisector of the nearest target apex that, when acquired, minimizes the effort of acquiring the actual target (see U.S. Pat. No. 5,880,723 for full disclosures). A prediction of this reformulation of Fitt's Law is that when the cursor is positioned on an apex of the actual target, the user faces an infinite number of implicit targets centered on the apex bisector that can each be acquired with equal expenditure of effort. A test of this prediction entails determining whether users in repeated trials scatter the acquisition hits randomly along the apex bisector or concentrate them at some unpredicted point. An unpublished experiment conducted by the inventor to test this prediction found the prediction to be valid. An appraisal of the original version of Fitts' Index of Difficulty; namely: log2(D/W) helps show why this result is expected without need to refer to the more detailed disclosures of U.S. Pat. No. 5,880,723. Consider a cursor located on an apex of an actual target. Consider also an arbitrary circle inscribed between the sides of this apex such that the circle is centered on the apex bisector and has tangency with each side forming the apex. Fitts' Law implies that during repeated trials that acquire the circular target the hit footprint will be centered on the circle center with the hits distributed around this point because of such human characteristics as muscle fatigue, varying levels of eye-hand coordination, inattention, etc. Fitts' Law defines “W” for the circular target to be twice its radius, “r”, with “D” being the distance from the apex to the center of the circle. Defining θ as one-half the apex angle we have D=(r/sin θ). It follows that:   ID  =                    log        2            ⁡              (                  D          W                )              =                  log        2            (                                                  2              ⁢              r                                      sin              ⁢                                                           ⁢              θ                                            2            ⁢            r                          =                                            log              2                        ⁡                          (                              1                                  sin                  ⁢                                                                           ⁢                  θ                                            )                                .                    Thus, because the ratio of radius to distance is constant for each possible implicit target, the value of ID depends only on the angle subtended by the apex and not the distance to the circle center. It also follows that as the angle of the apex increases the physical effort to acquire the target decreases. Thus, as the number of STB regions decreases the physical effort of acquiring a primary or secondary target decreases.
This result explains why knowledgeable users will acquire the primary and secondary target of a STB via a click in the converging portion of the region containing the target icon. Consider the case illustrated by region 6B42 of FIG. 4A. The largest implicit target that can be inscribed within the convergent portion of this region is the circle tangent to four segments of the region's boundary; i.e., tangency with each side of the converging component and tangency with each side of the horizontal component. The radius of this circle is greater than the radius of the inner-most circle of the horizontal component; i.e., the circle inscribed within the horizontal portion of the region having tangency on three sides. It follows that the distance to the circle of greatest radius is less than to the circle of smaller radius. Consequently, the effort to acquire the largest circle inscribed in the convergent portion of the 6B42 region is less than the effort to acquire the most easily acquired circle that can be inscribed within the horizontal portion of the 6B42 region. Since it was shown above that equal effort is expended to acquire any circle inscribed within the converging area of a region, it finally follows that it requires less effort to acquire the region by a click within the converging area than to acquire the region by a click in any portion of the horizontal area. A similar argument can be applied to any other region of the Spider graphic.
The value of the ID resulting from a TTB manipulation derives from the user traversing the cursor to the top of the window and onto the target icon, clicking, and then traversing the cursor back to some location frequently having lesser “W” than that of the icon; i.e., acquiring the icon commonly requires less effort than the effort of returning to the original work area. Quite different user actions determine the value of the ID when manipulating a STB. At display of the STB the cursor is positioned under computer control near the center of the STB central-area. For other than primary or secondary targets, the user traverses from approximately the center of the STB into the desired target area and clicks. Unless the toolbar is configured to permit multiple selections or a child control has been requested, the STB is then removed and the cursor is returned under computer control to the location occupied immediately before the STB display provided the user has parameterized for this capability. If it is presumed that both format styles employ icons of the same size, acquiring standard targets via a STB will require less physical effort than acquiring the same target via a TTB. Since it has been shown above that the effort of traversing into the converging portion of a region is less than that of a traverse into the closest target in the horizontal portion of the region it follows that it requires less effort to acquire a primary or secondary target by remote acquisition via a STB than to acquire the same target via a TTB.
The efficacy of activating a target by remote acquisition will depend on the frequency with which differing regions are entered and on the frequency of individual target acquisition within the region entered. Assume a STB of fourteen regions and that each region contains a minimum of two targets. Assume now that each of the fourteen target groups is referenced with approximately equal frequency but that within each target group the targets are selected with distinctly unequal frequencies. Finally assume the user correctly declares that the two most frequently accessed targets of each region can be activated by remote acquisition. Under this scenario the user can access each of the 28 most frequently used targets via a traverse of perhaps 0.75 inches terminated by a single or double click. If, as anecdotal evidence suggests, as much as 90% of toolbar manipulation is accomplished using fewer than 28 icons, it follows that under this scenario as much as 90% of all icon activations can be performed via the remote acquisition technique provided by the STB design. A scenario of somewhat lesser benefit arises when targets within each group are acquired with approximately equal frequency. In this case the physical effort expended during toolbar use is greater than in the preceding scenario since it is no longer possible to presume that most targets acquired can be activated by remote acquisition. While this latter scenario is not as advantageous as the preceding scenario, a user facing even this less advantageous scenario will still be expected to expend notably less physical effort using a STB than when using a TTB.
While exigencies of a particular application may suggest otherwise, full benefits of the Spider Toolbar design are normally achieved by considering the order in which targets appear within their region. To maximize benefits of remote acquisition it is suggested that targets be ordered within their respective regions such that targets declared for remote acquisition are most distant from the central-area. Any remaining targets can then be positioned such that the most frequently activated of these is closest the central-area, the second most frequently acquired is next closest to the central-area, etc. It is shown above that a click anywhere within the converging portion of a region requires equal effort and that a slightly greater effort is required to acquire the innermost target of the rectangular region. To maximize this effect, target shapes should be developed to minimize the traverse distance to the innermost target of each region. As illustration, consider that the target configuration of FIG. 2G1 entails a somewhat greater physical effort to access the “{circle around (x)}” target than is the case if the target boundary extends to the near-apexes of the region in the manner exemplified by the “{circle around (x)}” target of FIG. 2H1.
It can be quantitatively illustrated that when the hand is positioned on the mouse the functionality attached to targets located in the central-area can generally be activated with less physical effort than is expended using key-equivalent methods, the current technique that requires least physical effort. Consider the following indicative values based on measurements taken from a typical PC keyboard and a prototype Spider toolbar. Assume the CUT function can be activated via a click on a central-area shape or via simultaneous stroke of the “Ctrl” and “X” keys. Assume, further that the “Ctrl+X” combination is performed using the recommended touch-typing sequence of a right little-finger traverse from “;” to “Ctrl” and a left ring-finger traverse from “S” to “X.” The approximate physical effort expended to perform this key-equivalent sequence is 2.40 bits and 0.55 bits to stroke the “Ctrl” and “X” keys respectively for a total physical effort of 2.95 bits. Assuming the hand is on the mouse, the physical effort of acquiring a central-area function will be found to be 0.13-0.19 bits. Thus, activation of the “Cut” function via acquisition of a central-area shape requires less than one-tenth the physical effort expended to do so by the key-equivalent alternative. It is to be noted that the CUT key-equivalent was used for the illustration since CUT is one of the least physically demanding key-equivalent combinations. Comparison of other key-equivalent combinations will generally compare less favorably with central-area function activation than will comparison with the CUT function. When the central-area is used for other than management of the toolbar sub-system, maximal benefits from central-area targets are realized when: (1) a few functions are activated with high relative frequency, (2) the user correctly identifies these functions, and (3) the user declares these functions as central-area targets.
FIGS. 1A and 1B visually illustrate the manipulation differences required by the TTB and STB designs while performing the tasks of: (1) rotate the trapezoid, (2) set the string “receive some bold font” to bold, and (3) cut the string “This is a string . . . before paste.” and paste it over the string “indicated here.” In both figures the “+” symbol denotes the initial cursor location. In these figures the notation “1Lxx” commences and “1Lxx+1” terminates a user directed traverse. With the STB this notation results in two occurrences of some of the 1Lxx notation since the cursor is jumped to the center of the toolbar at STB activation and presumed jumped back to its pre-toolbar location at STB termination. Subscripts are employed to provide needed differentiation; i.e., 1 Lxx1 and 1 Lxx2.
With both designs, the initial traverse is to the trapezoid. To rotate the trapezoid by some unspecified amount, a person using TTB traverses to the “rotation” target at the screen top, 1A03, single clicks, and then traverses to the next target at 1A04. The person utilizing STB single clicks the middle button (or other activator as specified) to pop-up the toolbar display that simultaneously jumps the cursor from the trapezoid, 1B021, to near the center of the central-area at 1B022. In the exemplar toolbars of FIG. 1B circular targets and squares with rounded corners denote the primary and secondary targets respectively. Square targets identify standard targets that must be acquired by direct access. Because the “rotation” target is square the user must traverse the cursor from 1B022 to 1B031. When the user clicks on the rotation target, rotation is performed, the STB is unpainted, and the cursor jumped to its pre-STB activation location, now relabeled 1B032. For reasons apparent from U.S. Pat. No. 5,880,723 an experienced user employing the TTB toolbar will likely target the “t” of “font”, 1A04, and drag to the “r” of “receive”, 1A05, to illuminate the “receive some bold font” string. The experienced STB user will likely illuminate this string by traversing to the “r” of “receive”, 1B04, and dragging to the “t” of “Font”, 1B051. Once the string specified for bold font is highlighted the TTB user will again traverse to the screen top for a single click on the “B” icon, 1A06. The cursor is now traversed to the best location to commence illumination of the “This . . . paste” string which, to the experienced user, will be the “e” of “paste”, 1A07. Once the “receive . . . font” string is illuminated the STB user will pop-up the toolbar display. Since the bold function is displayed as the circular target in its target group, the group's primary target is the “Bold” target and thus can be acquired via a single left click in any non-target area of the group's region. As shown above, the experienced user will generally traverse into the converging portion of the target's region just beyond the border of the central-area and single click. The string is now set to bold, the STB unpainted, and the cursor jumped from 1B061 to 1B062, originally labeled as 1B051. The next goal under both systems is to illuminate the string “This is . . . before paste.” To accomplish this the TTB user will likely perform a traverse from 1A06 to 1A07 and drag to 1A08. The STB user performs the lesser initial traverse from 1B062 to 1B07 followed by a drag to 1B081. It is to be noted that whereas the cursor movement that illuminates the string once the start point is achieved is equal for each of the toolbar systems, there is a notable difference in the traverse distance required by the two toolbar systems to reach the start point. To perform the “Cut” the TTB user must again traverse to the screen top to click the “cut” icon, 1A09. The STB user pops-up the toolbar. Because “Cut” has been designated a central-area target of the STB it can be acquired by a traverse of perhaps 0.25 inch followed by a single click. The STB user will traverse from 1B082 to 1B091, to activate CUT. The cursor is jumped to 1B092, the user traverses it to 1B10 then drags to 1B111. The STB is again displayed and a traverse of about 0.25 inch is made from 1B112 to the central-area target “Paste”, 1B121, followed by a final click. The TTB user must perform the much longer traverse from 1A09 to 1A10 with a drag to 1A11 to illuminate the string. A final traverse to the screen top is now required in order to click the paste icon, 1A12.
Utilizing measurements taken from diagrams drawn to scale, FIG. 1C summarizes quantitative results of this example. It is seen under the heading “Physical Effort”, sub-heading “Per Traverse” that the total physical effort expended is 51.40 bits with the TTB and 30.24 bits with the STB. Total physical effort to perform the tasks by the STB is thus about 59 per cent of that required by the TTB. Performing the task set, however, includes activities common to both designs that entail expenditures of 15.13 bits of effort. Deleting the common activities from total effort expended from both manipulations gives specific indication of the relative effort required to perform the activities that relate only to toolbar manipulation. Resulting values presented under the sub-heading “Toolbar Specific” show that effort actually expended to be 36.26 bits and 15.11 bits to manipulate the TTB and STB respectively. For this illustrative exercise the effort expended during actual manipulation of the STB design is approximately 42 percent that of the TTB design. This example does not illuminate the extent of anticipated benefit that STB usage has on reducing “a” or the effect on “b” of using more efficient components of the musco-skeletal system. Based on analysis presented above it can, however, be concluded that the actual benefit of STB usage over TTB usage is greater than these results suggest.
It has thus been demonstrated through application of the theoretical tools developed and used by the most knowledgeable practitioners of these arts that a toolbar display of the type disclosed by this invention is expected to permit more rapid target acquisition than traditional toolbars.